This project will continue to pursue the study of cellular and tissue mechanisms in the remodelling of the structure of the lung. Work will progress simultaneously on several aspects of pulmonary biochemistry and pathology. Emphasis will be placed on the mechanisms involved particularly in several experimental models of pulmonary disease. Refined biochemical techniques will be applied to study the synthesis and degradation of elastin to study changes in the pulmonary connective tissues during experimental fibrosis and to measure lysyl oxidase. Additional effort will include the isolation of elastase from the alveolar macrophage and the continued effort to understand better the mechanisms involved in the development of elastase emphysema. Elastin precursor molecules (tropoelastin and proelastin), will be studied and enzymes associated with these molecules will also be investigated. The urinary excretion of elastin breakdown products will be investigated in several disorders that involve the lung and other organs.